Trephine.



W. H. HUDSON. 'TREP'HINR APPLICATION FILED AUG. 8, `1908.

Patented Aug. 10,'1909.

WILLIAM HENRY HUDSON, OF MONTGOMERY, ALABAMA.

TREPHINE.

ne. ceden Specification of Letters Patent.

Patented Aug. 10, 1909.

Application filed. August 8, 15908. Seria1 No. 447,579.

To all whom it may concern:

Be it known that I, `W1LLIAM HENRY HUD- .soN, a citizen of the United States, residing at Montgomery, in the county of Montgomery and State of Alabama, have yinvented certain new and useful Improvements in Trephines, of which the following is a specication.

The present invention relates to that class of surgical instruments known as trephines.

It has for its object the provision Aof an instrument which will eliminate the danger, heretofore present in trephining, of cutting through the bony structure of the skull and puncturing the covering of the brain or the brain proper, unless the utmost carebe exercised and the depth of the cut be accurately gaged by frequent observations during the operation. rI`his elimination of dangerous cutting is secured by providing the instrument with means for effecting an automaticl stopping of the advance of the cutting portion so soon such cutting portion has perforated the skull and resistance to the action of the cuttinor portion ceases; and, stated more specifically, the invention contemplates providing a trephining instrument with cutting teeth, combined with which are stopping wings adapted to engage the wall of the perforation and stop the advance of the toolimmediately the cutting teeth have perforated the bone andresistance to the action of the cutting teeth ceases.

In order that the invention may' be thoroughly understood by those skilled in the art to which it belongs, I have illustrated in the drawings herewith several embodiments of my invention, and in said drawings, Figure 1 is a side'view of a trephine constructed in accordance with my invention. Fig. 2 is a sectional view of the trephine shown in Fig. 1. Fig. 3 is a bottom view of the same. Fig. 4 is a side view of a perforator. Fig. 5 is a bottom View of the pcrforator,shown in Fig. 4. F ig. 6 is a side view of the follower. l? ig. 7 is a bottom view of the follower shown in Fig. 6.

Referring tothe drawings by numerals, like numbers indicating like parts in the several views, 2 indicates the shank' of the tool, which is of ordinary or'any desired construction and adapted to be placed in a hand-bit or engine-chuck, as may be desired. The active head of the tool comprises cutting teeth fi (see Fig. 1), which are of the type commonly used in trephines, and' which form the active entering or perforating portion pf the tool, and which, when the tool is operated, penetrate the bone and feed forwaad in the usual manner. Extending frdm said cutting teeth 3, but at an angle thereto axis of the tool, as shown.

The wings 4 are somewhat sharply inclined to the vlongitudinal axis of the tool long as theteeth find resistance to their cutting action, but so soon as thecutting teeth 3 perforate the bone and resistance ceases, the wings 4 take on a screw-like action and, biting in the wall ofthe perforation, check the tool and bind it against further advance.

As is well known the skull at its thicker portions presents a structure of different character being made up of ahard outer plate, an intermediate spongy or cellular structure, and an inner hard plate, and in order that the tool may not be checked when the cutting teeth enter the intermediate or wings 4 continued in .the saine direction around the head or body of the trephme owing to the temporary reduced resistance enter the cellular portion and the resultant tendency to lock and bind, I preferably pro` vide the extension wings 5 which, as clearly shown in Fig. 1,are not so much inclined. to the longitudinal axis of the tool. as are the wings 4 andare practically continuations of the wings 4, being joined thereto at the point 7 on curved lines. I have found that by thus varying the angles' of the two sets of stopping wings 4 and 5, danger of checking the tool when the cutting teeth strike the v'cellular portion of the skull is eliminated, and that the tool as thus made will feed through this cellular structure which offers less resistance, and will only be checked or stopped. vwhen resistance to the of an actual perforation and complete severance of the button.

Preferably the wings 4 and; 5 are' sep.- arated by round grooves 6' so that good clearance will be secured-and. danger of 4 and 5 on a curve as shown at 7 instead of at an abrupt angle,a much smoother operation of the tool 1s secured.

and will follow the lead of the teeth 3 so,

to the advance of the cutting teeth as theyy choking the tool with bone dusteliminated, and I nd further that by joining the wings are wings 4, the said wings 4 being arranged also at an angle relative to'the longitudinal cellular layer, as would be the case if the action of the cutting teeth occurs by reason in the same manner as ter-pin body will within the bore otparticlesiof bone dust jamming between center-pin 8 in a relation lto the point In the forml of the tool shown in Fi s. 1, 2, and 3', in which'a hollow or button-torming trephine is Ashown with my inventionapphed thereto, the usual center-pin 8 is provided, but the center-pin as invented by me has a body portion 9'provided with alternate ribs and grooves which formrclearance channels between the inner Wall of the trephine bore and the body-portion' 9 of the centerpin 8. By this construction, while the cenhave a close siding fit of the trephine, al danger the body '.9 of the centerthe trephine bore is eliminated, as these particles will pass into the clearance grooves. Furthermore. these clearance grooves have the add-itional function of en agin the center-pin holding-lug 11() -(see Fi so that when the center-pm -is inserte any one of pin and the Wall of the clearance grooves may engage the hold- -ing-lug lO'and the necessity of inserting the certain angularA relation in the trephine boreto engage said lu is done away'with. The body portion 2 o the tre` phine is provided with the usual slot 11 in one side to permit4 the center-pin or the bone button to be pushed out, 'and said slot 11 opens into an elongated bore 12 which 'receives a relatively shorttail 13 extending" upwardly from the body-portion 9 of the center-pin 8, this extended bore providing a relatively laro'e opening 'and one in which .there is no daan er of` dust collecting and jamming the tall 13 of the center-pin 8 when it is inserted. Preferably the tail 13 is provided with alternate ribs and grooves the body 9 so as to prevent jamming and provide clearance spaces for bone dust. l f

In the form of the tool shown in Figs. etf

and 5, in which a perforator is "shown, an ordinary diamond-shaped point 16 is' provided, and from this point extend wings 17 and 18, the wings 17 running directly from the point 16, as shown'in Fig. 5, while the wings 18 branch from' the wings 17 just below or away from thepoint 16, the said wings 18 it will be apparent have a different 16 than do the wings 17, the Wings 17 being extended from the point on each side so as to form together with the point 16 the drilling and cutting instrumentality, while the wings 1.8, since they do not come to the center 16 but branch from the periphery of the cutting wings 17 at ,points oii'set or to one side of the point hold'of the wall ot the lieve that l am the like fashion, biting into the wall of the per? foration and binding the tool against further rotation in the same manner as in the form showny in Figs. l, 2 and 3. In the adaptation of my invention shown in Figs. 6 and-7, it is applied to a follower, designed to follow the preliminary perforation made by the perforator just described, in which the cuttinfr teeth 14 lie across the face of the tool and meet at a smooth dull center 14Sl instead of having a hollow or bored-out body-portion, so that while the lcutting teeth 14 have an efficient action, the point leta is smooth and has no penetrating action this tool being adapted to drill a clean perforation instead of cutting out a button, as in the. form heretofore described. This action of the teeth is the same, and their angular relation is generically the saine as that described in connection with the other forms, for when the cutting teeth 14 perforate the bone and resistance to their advance ceases the stopping teeth-or wings 15 take perforation and stop the advance of the tool.

It will be seen that in several forms shown, so long as the cutting teeth or point find an active resistance to' 'their advance they will continue to cut and feed forward under the necessary pressure, while the stopping wings will simply follow without biting into the wall of'the erfora` tion until the perforation is complete l by the cutting teeth or point and resistance to their advance ceases, whereupon the stopping wings will operate with a screw like action, biting into t e wall of the perforation and stopping the tool at once, so that the operator, by the checking of the tool, will not only be advised of completion of the perforation, but unless an enormous turning pressure be applied sullicient to splinterl or shatter the skull area surrounding the perforation, he will be unable'to advance the tool further.

While l have shown a particular embodiment ot my invention, I wish it to be understood that this is merely illustrative and not restrictive of my invention, and as l befirst to provide a tool of the character described, which has means for automatically stopping its advance so soon as the cutting teeth cease to meet 4with resistance, I do not limit myself to anyof the details shown and described except so far as I am limited by the prier art to which the invention belongs.

Having fully disclosed my invention, I claim:

1. A tool of the class'dcscribcd having cutting means, and means operative to stop the ladvance of thetool immediately resistance to the advance of said cutting means ceases.

'2. A tool 'ofthe class described having cutting means, and stopping wings operative to stop the advance of the tool immediatel7 resistance tothe advance ofthe cutting means ceases. I'

3. A tool of the class described having cutting teeth, and 'two .,se'ts of stopping wings angnlarly disposed,v relative to each.'T

other. l

4. A tool of the `class described having cutting teeth and two sets of angularly disposed stopping Wings the active edges of `which wings merge on a curve,y 5. A tool of theolass described having a perforat'ing crown, and stopping means ad jacent said crown to engage the'l wall. of the perforation and sto the advance of the tool immediately resistance to the advance of the perforating crown' ceases.

(3. A trephine having a removable centerpin provided with grooves extending from one end to the other.

- 25 7. A trephine having a removable centerpin provided with alternate parallel ribs and grooves extending longitudinally f ronr one end to the other,

S. A trephine .havingaremovable centerpin having alternate `V-shaped ribs and' grooves extending from one end to the other.

In testimony whereof I4 affix my signature in presence of two Witnesses.

WILLIAM HENRY HUDSON. Witnesses:

' Q. P. SILER,

J. L. BoRRow. 

